0.36×8.5+6.4×0.85＝0.36×8.5+0.64×8.5＝（0.36+0.64）×8.5＝1*8.5＝8.5
0.36×8.5+6.4×0.85=0.36×10×0.85+6.4×0.85=3.6×0.85+6.4×0.85=（3.6+6.4）×0.85=10×0.85=8.5
